Spermatogonial Transplantation

精原细胞移植

基本信息

批准号：
7230987
负责人：
MICHAEL D GRISWOLD
金额：
$ 24.43万
依托单位：
WASHINGTON STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-01-01 至 2010-05-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): This renewal application will focus on an observation made in the first 4.5 years of this grant. It was found that gonocytes isolated from mice before or right after birth up until about 3 days after birth could not function efficiently as stem cells in transplant experiments. Cells isolated from animals 4 days plus after birth functioned efficiently as stem cells in these same experiments. The time period for this appearance of transplantation competent cells coincides roughly with the resumption of gonocyte mitosis and the migration of the gonocytes from the interior of the tubule to the basement membrane to form A spermatogonia. Preliminary studies indicate that some of the gonocytes from 3 day old or younger animals migrate to the basement membrane and may even undergo some mitosis but they always fail to initiate spermatogenesis. Even weeks after transplantation a few gonocytes remain on the basement membrane but no colonies of spermatogenic cells are formed and these immature gonocytes fail to function as spermatogenic stem cells. It is our hypothesis that changes in gene expression that are occurring in gonocytes are crucial to the formation of functional (i.e. transplantation competent) germ line stem cells referred to as the "maturation" of gonocytes. The experiments proposed in this application will investigate this hypothesis and attempt to define what changes in gene expression take place during this time in both gonocytes and in testicular somatic cells. The major advantage of our approach is the use of stem cell transplantation as an assay for functional stem cells. Experiments are proposed in 3 Specific aims: 1) Determine if cell culture conditions can transform gonocytes into transplantation competent stem cells. 2) Determine what changes in gene expression occur in the gonocytes and the somatic cells to allow the transformation into transplantation competent stem cells. 3) Test the role of candidate genes in the maturation process using the RNAi system to inhibit specific mRNAs. The proposed studies have significance in obtaining a basic understanding of what is required to form a spermatogenic stem cell and in gaining more practical insight into what manipulations could possibly be performed on primordial germ cells and gonocytes to create a source of cells for transplantation. This research could have implications in approaching human infertility problems where the maturation of primordial germ cells or gonocytes into functional stem cells is aberrant.

描述（由申请人提供）：此续签申请将集中于本赠款前4。5年中的观察。发现在移植实验中，直到出生后约3天后，直到出生后大约3天才能有效起作用，直到出生后至直到3天才能有效发挥作用。在这些相同的实验中，从动物中分离出的4天加分别为干细胞有效地起作用。这种移植能力细胞的出现时间段与恢复性别细胞有丝分裂的恢复和淋巴细胞从小管内部迁移到地下膜形成精子症。初步研究表明，来自3天或年轻动物的一些肿瘤细胞迁移到地下膜，甚至可能患有有丝分裂，但它们总是无法启动精子发生。即使在移植后的几周，地下膜上仍有几个肿瘤细胞，但没有形成精子生成细胞的菌落，这些未成熟的肿瘤细胞无法充当精子生成干细胞。我们的假设是，在肿瘤细胞中发生的基因表达的变化对于形成功能（即移植胜任）生殖系干细胞的形成至关重要。本应用程序中提出的实验将研究这一假设，并试图定义在这两个肿瘤细胞和睾丸体细胞中的基因表达发生的变化。我们方法的主要优点是使用干细胞移植作为功能干细胞的测定法。在3个特定目的中提出了实验：1）确定细胞培养条件是否可以将肿瘤细胞转化为移植统一的干细胞。 2）确定基因表达发生了什么变化，在肿瘤细胞和体细胞中会发生什么，以使转化为移植竞争能胜任的干细胞。 3）使用RNAi系统抑制特定的mRNA，测试候选基因在成熟过程中的作用。拟议的研究在获得形成精子干细胞所需的基本理解方面具有重要意义，并在对原始生殖细胞和性腺细胞上可能执行哪些操纵的方式获得更实际的见解，以创建用于移植的细胞来源。这项研究可能对接近人类不育症问题有影响，在这种问题中，原始生殖细胞或性腺细胞成熟到功能干细胞中的成熟是异常的。